[cybertechcafe]

I am looking for a grouping + scheduling tool that I can keep all of my employees (and me) in sync both in and out of the office. In the office, we have a mix of MS Windows (all XP Pro with Office 2003), Mac (OSX with NeoOfficeJ) and Linux (mostly Ubuntu 6.0.6). We have a couple of road warriors that all have Palm Treo 650's. Up to now, we've used a hobbled together group of tools to stay in contact (IMAP mail, iCalendar calendars and Mozilla Sunbird) but it's quickly getting unmanageable. I would like to find a product that will give us what, I believe, Zimbra will give us. I have found two components that seem to be lacking though:

1) Task manager. I do see the calendar and the ability to set + track appointments do group scheduling, but I don't see anything for tracking tasks (think the 'Task' option in MS Outlook). Did I just miss that or is it lacking?
2) Zimbra Mobile + Treo 650. It looks like the Zimbra Mobile just lets you do OTA sync for email, which is something that I can do already via IMAP (or POP3). Is there also an option for doing OTA syncs of your subscribed calendars (your calendar + any other calendars you have access to)?